Advice On Buying Lens

Hi allI just bought a D3200 DSLR from Nikon. I am totally a beginner in photography, after reading dozens of review from the internet and forums, I got that camera (if that camera has flaw please do not mention it here because it could digress the subject ). I want to ask for any advice on buying lens for this camera. My main focus will be on taking portrait and landscape photos so which lens should I buy for that purpose? Please advise me about this and since I am a beginner and my finance is not really high, I just want a medium type of lens (not professional or something luxury). Any help will be very much appreciated.Thank you.